Passwords To Keycards: 10 Types Of Digital Access Controls Compared

Using various digital technologies, it’s possible to restrict access to physical areas and computer systems. This post compares 10 different types of digital access controls, their applications, their benefits and their drawbacks.

1. Passwords

Passwords are the most popular primary form of access control for computer systems, accounts and devices. A strong password (over 12 characters and containing a mixture of uppercase letters, lowercase letters, numbers and symbols) will keep out most unauthorised users, but passwords do still have their vulnerabilities, and so secondary forms of authentication are increasingly becoming more necessary.

2. Passkeys

Whereas passwords can contain letters and symbols, passkeys are made up of just numbers. They are weaker than passwords, but often used for convenience to gain access to devices or to set alarms. PIN numbers are another example of passkeys.

3. Security questions

A security question is a personalised question that only the user knows the answer to. They were once a common form of secondary authentication, but their susceptibility to phishing has resulted in them becoming less commonly used in recent years.

4. One-time-passcodes

A more popular form of secondary authentication used alongside a password is a one-time passcode. This involves sending a code to a user's email address or phone number that can only be used once - and usually only within a certain timeframe. This is typically more robust than a security question.

5. Facial recognition

This involves using a camera to authenticate a person by scanning their facial features. Facial recognition technology requires a person to be using a device with a camera (such as a smartphone, webcam or specialist video doorbell). Although technologies like deepfaking exist, it is largely a difficult form of authentication to hack, and because of this is a common form of secondary authentication alongside a password.

6. Fingerprint scanning

Another form of biometric access control is fingerprint scanning. This requires a specialist device that can read a person’s fingerprint. Everyone’s fingerprint is unique, making this a robust form of access control. However, given that many devices do not have fingerprint scanners, it is limited to certain hardware.

7. Voice recognition

It’s also possible to confirm a person’s identity by authenticating a recording of their voice. This is not as common as other forms of access control, but is sometimes used to confirm a person’s identity over the phone. Specialist software can be used to analyse a person’s voice and confirm their identity.

8. Automatic license plate recognition

Automatic license plate recognition or ALPR involves taking a picture of a vehicle’s license plate. ALPR systems are commonly used as a form of vehicle access control into restricted parking lots or private grounds. The camera scans the registration number of each vehicle and if it’s recognised on a system it triggers a gate or barrier to open.

9. Keycards

Keycards can be given out to authorized individuals and used as a form of physical access control for opening doors or parking lot barriers. While keycards can be shared, stolen or lost, software can be used nowadays to remotely track and disable them - making less of a security risk and a convenient form of physical access control.

10. IP authentication

This form of authentication involves checking a user’s IP address. It is sometimes used to grant access to websites, email addresses or cloud servers. If a person is found to be trying to gain access from an unfamiliar IP address, they may be blocked and will have to authenticate their identity via another form of access control. This can help to fend off remote cybercriminals.

Access Control Type	Application	Benefits	Drawbacks
Passwords	Primary access for computer systems, accounts, and devices.	Most popular and widely used; can be strong with a mix of characters.	Vulnerable to unauthorized access; requires secondary authentication for better security.
Passkeys	Gaining access to devices or setting alarms.	Convenient and quick for device access.	Weaker than passwords; only uses numbers.
Security Questions	Secondary authentication for accounts.	Simple to set up and remember.	Susceptible to phishing attacks and social engineering.
One-time-passcodes (OTP)	Secondary authentication for online accounts and services.	More robust than security questions; time-limited and single-use.	Relies on the user's phone or email security.
Facial Recognition	Secondary authentication for smartphones and webcams.	Difficult to hack; unique to the individual.	Requires a camera; can be susceptible to deepfaking technology.
Fingerprint Scanning	Biometric access for specialist devices (e.g., smartphones, laptops).	Unique to the individual; very robust.	Requires specific hardware; not available on all devices.
Voice Recognition	Confirming identity over the phone.	No hardware required; unique to the individual.	Not as common as other methods; can be affected by background noise.
Automatic License Plate Recognition (ALPR)	Vehicle access for parking lots and private grounds.	Automated and efficient vehicle access.	No such major drwabacks.
Keycards	Physical access for doors and parking lot barriers.	Convenient for authorized individuals; can be remotely disabled if lost.	Can be shared, stolen, or lost; software required for security tracking.
IP Authentication	Granting access to websites, emails, or cloud servers.	Fends off remote cybercriminals from unfamiliar locations.	Can be bypassed with a VPN; may inconvenience legitimate users with dynamic IP addresses.

Which form of access control should you use?

As you can see, there are many different types of access control. In many cases, the most secure solution is to implement multi-factor authentication. This involves using multiple layers of access controls to create a much stronger barrier that will repel the most persistent criminals.